// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_BASE_BITSTREAM_BUFFER_H_
#define MEDIA_BASE_BITSTREAM_BUFFER_H_

#include <stddef.h>
#include <stdint.h>

#include "base/macros.h"
#include "base/memory/shared_memory.h"
#include "base/time/time.h"
#include "media/base/decrypt_config.h"
#include "media/base/media_export.h"
#include "media/base/timestamp_constants.h"

namespace IPC {
template <class P>
struct ParamTraits;
}

namespace media {

// Class for passing bitstream buffers around.  Does not take ownership of the
// data.  This is the media-namespace equivalent of PP_VideoBitstreamBuffer_Dev.
class MEDIA_EXPORT BitstreamBuffer {
public:
    BitstreamBuffer();

    // Constructs a new BitstreamBuffer. The content of the bitstream is located
    // at |offset| bytes away from the start of the shared memory and the payload
    // is |size| bytes. When not provided, the default value for |offset| is 0.
    // |presentation_timestamp| is when the decoded frame should be displayed.
    // When not provided, |presentation_timestamp| will be
    // |media::kNoTimestamp|.
    BitstreamBuffer(int32_t id,
        base::SharedMemoryHandle handle,
        size_t size,
        off_t offset = 0,
        base::TimeDelta presentation_timestamp = kNoTimestamp);

    BitstreamBuffer(const BitstreamBuffer& other);

    ~BitstreamBuffer();

    void SetDecryptConfig(const DecryptConfig& decrypt_config);

    int32_t id() const { return id_; }
    base::SharedMemoryHandle handle() const { return handle_; }

    // The number of bytes of the actual bitstream data. It is the size of the
    // content instead of the whole shared memory.
    size_t size() const { return size_; }

    // The offset to the start of actual bitstream data in the shared memory.
    off_t offset() const { return offset_; }

    // The timestamp is only valid if it's not equal to |media::kNoTimestamp|.
    base::TimeDelta presentation_timestamp() const
    {
        return presentation_timestamp_;
    }

    void set_handle(const base::SharedMemoryHandle& handle) { handle_ = handle; }

    // The following methods come from DecryptConfig.

    const std::string& key_id() const { return key_id_; }
    const std::string& iv() const { return iv_; }
    const std::vector<SubsampleEntry>& subsamples() const { return subsamples_; }

private:
    int32_t id_;
    base::SharedMemoryHandle handle_;
    size_t size_;
    off_t offset_;

    // This is only set when necessary. For example, AndroidVideoDecodeAccelerator
    // needs the timestamp because the underlying decoder may require it to
    // determine the output order.
    base::TimeDelta presentation_timestamp_;

    // The following fields come from DecryptConfig.
    // TODO(timav): Try to DISALLOW_COPY_AND_ASSIGN and include these params as
    // std::unique_ptr<DecryptConfig> or explain why copy & assign is needed.

    std::string key_id_; // key ID.
    std::string iv_; // initialization vector
    std::vector<SubsampleEntry> subsamples_; // clear/cypher sizes

    friend struct IPC::ParamTraits<media::BitstreamBuffer>;

    // Allow compiler-generated copy & assign constructors.
};

} // namespace media

#endif // MEDIA_BASE_BITSTREAM_BUFFER_H_
